14 October 1967
Leading Articles
operations. Firstly, the incision must be through skin not
far distant from the anus, and intestinal bacteria are more
widely distributed over this area than is commonly realized;
among them the spores of clostridia are resistant to ordinary
methods of skin disinfection. Secondly, the operation entails
severing large masses of muscle in which bacteria from the
region of the incision can be directly implanted. Thirdly,
and most important, the disease which has necessitated the
operation reduces the blood supply to the area, and may thus
reduce the oxygen tension to a level permitting clostridial
growth. The degree to which this area is so affected is
doubtless one variable factor determining the outcome.
Others are the efficacy of skin cleansing and the toxigenicity
of the patient's own strain of Cl. welchii. This is a property
in which different strains vary widely.
This operation carries the imperative indication for penicillin cover in doses allowing for the fact that clostridia are
less sensitive to penicillin than, for instance, streptococci. At
least 500,000 units should be given at intervals of not more
than six hours for seven days.' Other operations with a
similar risk meriting penicillin cover were recently referred
to in our correspondence columns by M. J. Parker.5
Gas gangrene is a rare and terrifying condition, and it is
perhaps natural that operating-theatre staffs should regard it
as calling for exceptional measures. In fact it is much easier
to disinfect a theatre after a case of gas gangrene than after
a dirty operation on the lower bowel, because in the former
the organisms are all in the vulnerable vegetative form,
whereas in faeces they exist largely as resistant spores. That
most strains from the normal bowel are as toxigenic as those
which have had the opportunity of causing gas gangrene has
been shown by D. J. E. Price and R. A. Shooter.6 It remains
to be seen whether conditions in the operating-theatres
concerned in these recent episodes are considered to require
improvement. What can be said with some confidence is that
when gas gangrene follows thigh amputation there is no
need to look any further for the source of infection than the
patient's anus.
Standardization in Human
Cytogenetics
EDICAL IOURNAL
69
made in chromosome identification over the three preceding
years.
The report of the Chicago Conference, published recently,'
is perhaps one of the most important documents published in
the field of human cytogenetics. It considers new means for
describing the normal chromosomes and deviations from the
normal complement, and proposes an entirely new system of
notation for the uniform description of the human chromosome
set and its abnormalities. This shorthand system is also
applicable to the description of the somatic chromosomes of
non-human species, so that perhaps from this conference a
universal system of notation may eventually develop. The
system is most carefully designed so that it should be adaptable to automated data processing and information retrieval
systems, which are becoming more and more widely used.
Other topics discussed at the meeting included the recording of data, and recommendations are made in the report on
the essential information required if accounts of chromosome
abnormalities and variation are to have maximum value.
The place of autoradiography in chromosome identification
was considered as well as problems related to the automation
of chromosome analysis, population cytogenetics-and in
particular the types of population suitable for study and
the information which might be derived from such studiesand the effects of radiation and mutagenic substances on
chromosomes.
The conference needs following up in two important respects.
Its recommendation " that in view of the expansion in human
cytogenetics during the past six years it is now desirable to
explore the feasibility of establishing a central organization
for collecting and analysing data on the variability of the
human karyotype " should be acted on by the appropriate
international and national bodies. Secondly, its report is
available. If investigations and journals publishing papers
in this and related fields would use the system of notation
recommended in the report then the clarity of published work
would be considerably improved. In the past there has been
confusion, and valuable data have been lost by the publication
of inadequate and incomplete case reports. Widespread
acceptance of the recommendations of the Chicago conference
should make this a thing of the past.
The explosion in our knowledge of human chromosomes and
their abnormalities which has occurred during the past ten
years has resulted in many difficulties, particularly of communication and nomenclature. There have now been three
conferences to consider these problems. The first of these
was in Denver in 1960, the second in London in 1963, while
the third and last was convened at the University of Chicago
in September 1966. The aim of each of these meetings has
been to improve communication and understanding in the
field of human cytogenetics. At Denver order was brought
into the system of numbering human chromosomes, and the
international system agreed at that meeting has remained
essentially unaltered since. In London the Denver system
was consolidated and the alternative use of letters to classify
the different chromosome groups, which had been advocated
by some workers since 1961, was agreed internationally to be
a useful alternative to the Denver system of nomenclature.
At the conference it became clear that little progress had been
The Ministry of Health's team visiting the U.S.A. and
Canada to persuade British medical emigrants to return is now
at work. Can it offer the attraction that conditions are so
different from what they were, or what the emigrants thought
they were, that some will be tempted to return ? The
Ministry's views, as expressed by its Chief Medical Officer,
Sir George Godber, in his annual report,' are robustly hopeful of better times ahead for doctors working in both hospital
and general practice. That the department has its views also
on what the profession should be doing is apparent from Sir
George's observation that, " Given an acceptable and workable opportunity . . . the medical profession has shown its
ability to work constructively and successfully with the
department."
In his introduction Sir George dwells on the year he is
reviewing, 1966, as one that " may well be seen in retrospect
Chicago Conference: Standardization in Human Cytogenetics. Birth
Defects, Original Article Series, 1966, Vol. 2, No. 2, New York.
Copies can be obtained free from the Medical Department, The
National Foundation-March of Dimes, 800 Second Avenue, New
York, N.Y. 10017.
On the State of the Public Health, The Annual Report of the Chief
Medical Officer of the Ministry of Health for the Year 1966. 1967.
H.M.S.O.
2 Management Functions of Hospital Doctors, Ministry of Health, 1966.
H.M.S.O.
I
Health Priorities